1. Field of the Invention
The present invention relates to construction of railroad cars, and more particularly, to unique construction of corner connectors of open top rail cars such as gondolas and hoppers which eliminate fixed end moments at the upper corner of the rail cars.
2. Description of the Prior Art
Heretofore in the art, the upper corner connection of open top rail cars, i.e., the connection of top side chord and the top end chord have been connected by welding or some other rigid, inflexible means of connection. These top chords form the upper edge of the side walls of open top rail cars and serve to reinforce the relative thin gauge steel of the side and end walls. Such corner connections are natural points of fixed end moments whenever forces are laterally applied to either the end walls or the side walls of an open top rail car. For example, during loading, excessive forces are often applied to the side walls because of sway or movement of the load being lifted into the rail car. Also, loads frequently shift during starting, stopping and humping of rail cars in the rail yard, or during movement of the rail car around sharp bends in the track. When loads shift and contact the side or end walls of the rail car, sudden shock forces are applied to the end and side chords of the walls, and such forces are naturally concentrated at the corner connections of the top side chord and top end chord of the open top rail cars. Since these side and end top chords have heretofore been rigidly connected by welding or other such means, such fixed end moments have resulted in fracture of the corner connection either as a result of metal fatigue or sudden excessive stress.
Accordingly, the present invention has been developed to overcome the deficiences of the prior art so as to provide a flexible corner connection that eliminates fixed end moments and premature failure.